Locking rings are used in a large field of applications, where parts have to be fixed on a shaft, a shaft stub or within a bore which can be provided in any type of material body. At present two general types of locking rings are known. The first type is circumferentially open. This general type is used in connection with a locking groove on the shaft or in the bore and is adapted to the dimensions of the groove, i.e. with respect to its width and its diameter in the mounted state. The locking ring includes a circumferential gap and gripping elements. The gripping elements enable closing and opening of the gap by the use of a corresponding tool which intermediately changes the general diameter of the locking ring by changing its circumferential length. Opening the gap allows the locking ring to be elastically deformed and moved into its final axial position close to the locking groove. Releasing the elastically deformed locking ring thereafter, will return the locking ring, via its spring forces, back into the direction of its “natural” diameter and thereby penetrate the locking groove to the maximum possible extent without further action by the tool or the like. One version of these types of locking rings, known as circlips, do not include a gripping area (elements) and thus do not require the use of a corresponding tool to elastically deform the locking ring.
The other general type of locking ring is circumferentially closed. Located inwardly or outwardly of the circumferentially closed edge zone are a number of equally spaced teeth. The teeth extend inwardly or outwardly, and make physical contact with the shaft or bore on which these so called tooth rings, or self locking rings, are to be placed. The teeth need to be rather elastically deformable and particularly adapted to the diameter of the shaft or bore for which the locking ring is to be used, because the teeth must be bent elastically in order to be pushed axially to their final position on the shaft or in the bore. It is possible to further move the locking ring in the axial direction even after mounting of the locking ring at least in one of two axial directions, since the teeth remain bent elastically during the whole period of their application to the shaft or bore. This holds true, even if the teeth can elastically snap into a locking groove which may be provided on the shaft or in the bore. The degree of security of axial holding force and the accuracy of the holding position of this general type of locking ring is rather limited.
For both of the aforementioned general types of locking rings, a material with a considerable spring force is needed, for instance hardened steel and particularly so called spring steel.
The first type of locking ring, being circumferentially open and having a gap, can be used to withstand considerable axial forces after being mounted. The second type of locking ring, being circumferentially closed, can be easily mounted but withstands—at least in one direction—relatively smaller axial forces while being mounted. In either case, it is necessary to make these types of locking rings with considerable “spring” properties and to ensure very precise dimensions in connection with the shaft or bore to which these locking rings are applied.
It is often necessary to provide a support washer which is axially placed next to the mounted locking ring in order to keep larger parts or groups of parts in a predetermined axial position with respect to the shaft or the bore. Typical applications include needle bearings where the needles roll along the circumference of a shaft, and where the needles must be kept in their axial position in a simple and space conserving manner. Other applications include certain types of gears, e.g. multi shaft gear rings or swivels.
Therefore, there is a need for an improved type of locking ring which is not only easy to manufacture, but also enables simple mounting of such locking rings, while exhibiting sufficiently high axial holding forces.